Drafting machine



2 Sheems-Sheei'l l Imm" Aug. 7, 1951 J. F. JOY

DRAFTING MACHINE Filed Dec. 26, 1946 Aug. 7, 1951 J. F. JOY 2,552,920

DRAFTING MACHINE Filed Deo. 26, 1946 2 Sheets-Sheet 2 Pate'nted u'g. i"7, 1951 UNITED STATES PATENT OFFICE y -K sceicco j u DRAFTNG MACHINE Y Joseph F. Joy,-Pittsburgh, Pa., assigner to Joy Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania 'Appiieauoneemter 26, `1946, serial No. 718,287

2 Claims.' 1. i.

This invention relatesV to `drafting machines and more particularly to improvements; in a universal drafting machine of the parallel` motion type whereby the flexibility andjrange of adjustment of the machine are greatly improved.

It is accordingly an object of the present invention to provide an improved universal drafting machine. A still further object is to provide an improved portable universal drafting machine v which may be readily folded intesa' compact relation for transport. These and other objects and advantages of the invention WHL-however, hereinafter more fully appear. A

In the accompanying drawings there is shown for purposes of illustration one form which the invention mayassume in practice.

In these drawings: y

Fig. 1 is a plan view of a drafting machine, constructed in accordance with a preferred illustrative embodiment of the invention.-

Fig. 2 is a side elevational view of the drafting machine shown in Fig. 1. n

Fig. Sis a vertical sectional view taken substantially on line 3-3 of Fig. 1, with the parts in folded transport position.

^ Fig. 4 `is an enlarged fragmentary Vplan view of the main protractor head shown in Fig. l; Fig. 5 is a View similar to Fig. l4, with the protractor arm adjusting means in released position, and with an angularly adjusted position of the protractor arm indicated in dotted lines.

Fig. 6 is an enlarged vertical sectional View taken substantially on line 6-6 of Fig. 1,illustrating details of the intermediate or auxiliary protractor head. Fig. 7 is a detail vertical sectional View taken substantially on lines 1-1 of Fig. 5, through the main protractor head. l y v Fig. 8 is an enlarged vertical sectional View through the main protractor head, said View taken substantially on line 8--8 of Fig. 1. Fig. 9 is a diagrammatic View showing the wide range of positions obtainable with a given anchor location, and showing the machine operating both to the left and tothe right of the anchor. In this illustrative embodiment of the invention, the improved'drafting machine'is generally 'designated I and generally comprises a portable anchor 2, pairs of pivotally connected parallel :motion connections 3 and 4, a main protractor head and an intermediate or auxiliary protractor head i. Swiveled on the main protractor headv is a protractor arm 1 carrying scales or rulers B, 8 arranged in right angular relation, asl shown in Fig. '1, and each provided with linear 'graduations along its opposite edges.

The portable anchor 2 includes a weighted base 9, herein having three equally spaced legs I0 provided with rubber-protected feet Il, so that firm three-point contact with a drawing surface designated S in Fig. 2, such as the plane top of i a desk or drawing board, is attained. A handle assume any known form and herein respectively comprise pairs of parallel arms or links Ill, I4 and I5, I5, and the outer ends of the outer links I4 are pivotally connected to parallel upright pivot pins IE secured to the top of the base 9, and these arms, at their inner ends, are pivotally connected to parallel upright pivot pins I1 secured to the top of a circular plate I8 (see Fig. 6) of the intermediate protractor head 6. The adjacent ends of the inner pair of parallel links I 5, I5 are pivotally connected to parallel upright pivot pins I9 secured to the bottom of a rotatable circular bottom plate 20 of the intermediate protractor head 6. The inner ends of the inner arms I5, I5 are pivotally connected to parallel upright pivot pins 2I secured to a circular top plate 22 of the main protractor head 5. This circular plate is provided with circumferential graduations 23, and the swiveled protractor arm 'I carries a pointer 24 whereby proper setting of the protractor arm may be readily determined. The pivotal axes of the pairs of parallel links are equally spaced apart and are so arranged and constructed that a parallel motion adjustment of the main protractor head 5 is afforded so Athat the zero graduation on the upper plate 22 may be maintained parallel to a horizontal line in all adjusted positions of the main protractor head.

The intermediate or auxilary protractor head 6 has a central pivot pin 25 (see Fig. 6) formed with an enlarged lower head 26 secured to the rotatable lower plate 20, and this pin projects axially through alined central openings in the plates 20 and I8. The upper portion of the pivot pin 25 is threaded for engagement with a rotatable clamping nut 21 provided with a knurled operating handle 28. Surrounding the pivot pin 25 and arranged between the top plate I8 and the nut 21 is a suitable washer 29. When the nut 2l is tightened, the plates I8 and 20 of the intermediate protractor head are frictionally clamped together iirmly to lock the parts in adjusted position. The upper plate I8 has circumferential graduations 30 and the lower plate has attached thereto, at diametrically opposite points, pointers 3|, 3| whereby the proper setting of the inter- 3 mediate protractor head may be readily determined.

The main protractor head 5, in this illustrative construction, has worm gear teeth 33 on the peripheral edge of the circular plate 22, and a tangentially arranged worm 34 is engageable with these gear teeth, as shown in Fig. 4. The worm is Lfixed to a rotatable horizonal shaft 35 journaled in a swiveled bracket 36 pivoted at 31 on an upright pivot screw secured to a circular bottom plate 38, herein formed integral with the protractor arm 1. Secured to the shaft 35 at the outer side of the bracket is an operating handle 39 whereby the worm 34 may be rotated. This handle has circumferential graduations 49, and a cooperating pointer 4I is secured to the bracket to provide micrometric adjustment of the protractor arm. The bracket 35 has an integral arm 42 projecting outwardly from` its pivot, and this arm is engaged at its outer end preferably by a bent wire spring 43. This spring is attached to a pin lili on the protractor arm and engages a pin 45 on thelever arm 42 so that the bracket 36 is swung on its pivotal mounting constantly to urge the worm 34 toward meshing engagement with the worm gear teeth. When the pin 45 is pressed inwardly to swing the arm 52, the spring 43 is compressed, swinging the worm Sii out of engagement with the worm gear teeth to the position shown in full lines in Fig. 5, thereby to free the protractor arm for swinging movement. The main protractor head has a central pivot pin 46 formed with an enlarged bottom head 41 which engages the bottom of the plate 3S and provides a smooth sliding support for the main protractor head as the latter is moved over the drawing surface. This pivot pin passes axially through alined openings in the plates 38 and 22 and is threaded at its upper end for engagement by a clamping nut 48 provided with a knurled operating handle 49. When the nut 48 is tightened, the plates 22 and 38 are frictionally clamped together to lock the protractor arm in its adjusted position.

The protractor arm 1, in this instance, has

three equally spaced radial arm portions I, 52

and 53, and the rulers or scales 8 are attached to the arm. portions 5l and 52 in right angular relation, as shown in Fig. 1. These rulers may be readily slidingly detached from these arm portions, and each ruler carries a clamping screw 5t receivable in a slot 55 of a slotted outer portion of the arm portions, and spaced pins 59 on the rulers also enter the slots 55 iirmly to hold the rulers in alinement with the arm portions when the screws 54 are tightened. The rulers are preferably each provided with a clamping screw and pin at its outer end so that either end of the rulers may be attached to the arm portions of the protractor arm. When it is desired to operate the machine in a left hand position at the left of the anchor 2, as viewed in Fig. 9, the upper ruler 8, shown in Fig. l, may be detached from the upper arm portion 5I and attaohed to the lower arm portion 53 in right angular relation to the horizontal ruler. By loosening the clamping nut of the intermediate protractor head G and by releasing the clamp and worm of the main protractor head 5, the main protractor head and the protractor arm may be shifted to the left through 180 from the position shown in Fig. l to enable the machine to operate as a left hand machine in the manner clearly shown in dotted lines in Fig. 9.

To obtain compactness during transport, the inner parallel arms I5, I5, when the clamping nut 21 of the intermediate protractor head is loosened, may be swung beneath the base 9 into substantial parallelism with the outer arms I4, I4 in the manner shown in Fig. 3. As the arms I5, I5, are swung beneath the feet I0 of the base, the arms, dueto their inherent resiliency, may be sprung downwardly suficiently to clear the feet, and when the feet are cleared, the arms may be released so that they assume the folded position shown between the feet. When the arms are in their folded position, a screw 51 may be inserted in a central opening 58 in the base 9 so that the lower threaded end 59 of the screw may be screwed into a threaded recess 60 centrally in the top of the operating handle 49 of the main protractor head clamp, and when the screw 51 is tightened, the parts are rmly locked in their folded position so that the machine may be readily transported.

The manner of use of the improved drafting machine will be readily apparent from the description given. When the parts are in the position shown in Fig. l and in full lines in Fig. 9, the zero graduation of the main protractor head 5 is maintained parallel to a horizontal line by the parallel motion connections 3 and 4, and during adjustment of the main protractor head, as for example, into the several dotted line positions shown at A, B and C at the right of the anchor 2 in Fig. 9, the lower ruler 8 is maintained parallel to a horizontal line with the upper ruler in a right angle position. By loosening the clamping nut 48 of the main protractor head 5 and releasing the worm 34 from the worm gear teeth 33, as shown in Fig. 5, the protractor arm 'I may be freely swung on its pivotal mounting relative to the main protractor head into Various angular positions, as for example, the dotted line position shown in Fig. 5. The worm bracket 36 may then be released so that the spring 43 moves the worm into meshing engagement with the worm gear teeth and then the handle 39 may be rotated to turn the worm to effect micrometric adjustment of the protractor arm. In any swiveled position of the protractor arm, the nut 48 may be tightened by turning the handle 49 firmly to lock the arm in adjusted position. If it is desired to move the zero graduation of the main protractor head 5 into an inclined position, as for example, to a position at a 30 angle as indicated in dotted lines in Fig. 1, the clamping nut 21 of the intermediate protractor head 6 may be loosened to permit rotation of the bottom plate 20 relative to the top plate I8, and when the inner arms I5, I5 assume the dotted line position indicated, the clamping nut 21 may again be tightened to hold the parts firmly in adjusted position. When the protractor head 5 is in the angularly disposed position shown in dotted lines in Fig. l, the protractor arm 1 may be swiveled into different positions relative to the main protractor head while the zero graduation of the latter extends in parallelism with the line of the 30 angle, thereby attaining rapid adjustment of the rulers 8, 8 without necessitating mathematical figuring of the angle each time an adjustment of the protractor arm is made. Obviously, the main protractor head 5 may be set at any desired angle without disturbing the angular setting of the main protractor head, and when the clamping nut 21 of the intermediate protractor head B is again released, the setting of the main protractor head may be quickly returned into its original position with the zero graduation parallel to a horizontal line.

By loosening the clamping nuts of the protractor heads and 6 and by changing the position of one of the rulers 8 with respect to the protractor arm, the machine may be quickly changed from a right hand machine, as shown at the right of the anchor 2 in Fig. 9, to a left hand machine, as shown to the left of the anchor in Fig. 9. When the machine is in its left hand position, it may be adjusted into the dotted line positions indicated at D, E, F and G in Fig. 9. The portable anchor 2 of the drafting machine may be placed at any desired location on the drawing surface S either at the left (Fig. 1) or at the right or may be centrally located, as shown in Fig. 9.

As a result of this invention, an improved universal drafting machine of the parallel motion type is provided which has increased iiexibility and range of adjustment over previous known devices. By the provision of the intermediate protractor head at the point of pivotal connection of the parallel motion arms, the main protractor head may be quickly adjusted to any desired angle without disturbing the angular setting thereof, thereby to facilitate manipulation of the protractor arm and, as a result, eX- pediting the making of drawings. It will further be evident that by provision oi the auxiliary and main protractor heads and the novel structure of the rulers and protractor arm, the machine may be readily converted from a right hand machine to a left hand machine, and vice versa.

By the feature of folding the parallel motion arms into substantial parallelism and by making the anchor readily portable, transport of the machine is facilitated. Other manners of usev and advantages of the invention will be clearly apparent to those skilled in the art.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be embodied and modified in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure :by Letters Patent is:

l. In a drafting machine, the combination comprising a portable anchor having a transporting handle and a weighted base adapted to be placed in any desired position on a plane drawing surface and by its own weight providing a fixed point for the machine, said base having `a body portion, a protractor head having a swiveled protractor arm, pairs of parallel motion connections operatively connected together and disposable in different angularly related positions for connecting said protractor head to said anchor, said connections arranged in superimposed relation, one in planes above said base and the other in planes, parallel to said first mentioned plane below said body portion of said base. and said arms being disposable in folded relation with said connections in substantial parallelism and with the swivel axis of the protractor arm located :below said body portion at the center of said base, said protractor head having lockreceiving means at the swivel axis thereof, and looking means on said :base at the center thereof and engageable with said receiving means for securing said head to said base, thereby to provide a compact transportable unit.

2. In a drafting machine, the combination comprising a portable anchor having a transporting handle and a Weighted base adapted to be placed in any desired position on a plane drawing surface and by its own weight providing a iixed point for the machine, said base having a body portion, a protractor head having a swiveled protractor arm, pairs of parallel motion connections operatively connected together and disposable in different angularly related positions for connecting said protractor head to said anchor, said connections arranged in superimposed relation, one in planes above said base and the other in planes, parallel to said iirst mentioned planes, below said body portion of said base, and said arms being disposable in folded relation with said connections in substantial parallelism and with the swivel axis of the protractor arm located below said body portion at the center of said base, said protractor head having a threaded boss at the swivel axis thereof, and a screw on said base at the center thereof and engageable with said threaded boss for securing said head to said base, thereby to provide a compact transportable unit.

JOSEPH F. J OY.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 334,470 Hanssen Oct. 30, 1906 965,483 Noyes July 26, 1910 986,358 Carmical Mar. 7, 1911 1,459,792 Nilant June 26, 1923 1,633,628 Fortin July 28, 1927 1,909,291 Little May 16, 1933 2,042,885 Fay June 2, 1936 2,242,827 Langsner May 20, 1941 2,287,987 Greenleaf June 30, 1942 2,331,382 Eubanks Oct. 12, 1943 2,366,225 Webster Jan. 2, 1945 2,407,235 Halstead Sept. 10, 1946 FOREIGN PATENTS Number Country Date 292,795 Great Britain June 28, 1928 674,736 France Oct. 22, 1929 

